Flushing oil composition



Patented Nov. 18, 1941' FLUSHING OIL COMPOSITION John A. Edgar and Harold A. Woods, Martinez,

Califi, assignors to Shell Development Company, San Francisco, Calif., a corporation of Delaware No Drawing. Application September 24, 1940,

Serial No. 358,129

2 Claims.

The present invention relates to compounded flushing oils for use in internal combustion engines.

As is known, deposits of lacquer, viscous asphaltic oxidation products of oil and lacquerbound solid particles form on piston rings, ring grooves, cylinder walls, oil lines, oil screens and crankcase walls of internal combustion engines during use. These deposits lead to piston ring sticking, interruption of oil circulation, increased oil consumption, abrasion of bearing surfaces and eventual engine destruction if not removed.

It has been the practice to attempt the removal of these undesirable engine depositsby flushing the engine with light mineral oils and/or various compounded preparations. It is an object of the present invention to provide an improved compounded flushing oil suitable for removal of the above-described engine deposits. Further, it-is an object-of the instant invention to provide a single compound with a double cleansing action, 1. e. both an excellent lacquer solvent and an excellent cleanser for-carbon sludge deposit removal. Still further, it is an object to provide a flushing oil having a sufliciently high flash point to enable its safe use under all conditions and one which is stable under storage conditions. Other pertinent objects are to provide a flushing oil having satisfactory lubricating properties, one that is rapid and thorough in its cleansing action and at the same time noncorrosive with respect to the various metal alloys used at the present time in internal combustion engine construction. Other objects will appear in the following detailed description of the inven-- tion.

Internal combustion engines become foule after continued operation by contamination of the lubricating oil with solid particles such as carbon, metal particles and road dust and by the gradual deterioration of the lubricating oil .and subsequent formation of lacquers. Several of the more specific serious effects which will occur if engine fouling is permitted to follow itsnormal course are as follows Solid particles-deposit in the ring grooves behind the piston rings, are cemented together by lacquer formation arising from lubricating oil deterioration and build up to such an extent that normal flexing of the ring is prevented; as a result, ring sticking ensues.

Solid particles entrained in an emulsion of system and in any case resulting in impaired,

faulty lubrication of the various parts of the en-.

glne.

Lacquer is deposited on cylinder walls, in severe cases in sufficient thickness tocause the piston rings tobe imbedded therein and effecting cementation of th piston rings to the cylinder walls, resulting in piston seizure when the engine is stopped.

Solid matter, oxidized oil products and water form sludge deposits on the crankcase walls, in

valve chambers and in other areas where there i is little agitation. These deposits are particuasphaltic material, oil and water, deposit on the oil screen and in small drilled oil passages, at times completely obstructing the 'oil circulatory larly harmful when they obstruct penetration of oil to the valve guides and similarly lubricated elements of the engine.

Lacquer deposits build up on top and bottom of piston rings and/or ring grooves, thus inhibiting such removal is usually attempted by utilization,

of cleaning agents which may be either added to or substituted for the lubricating oil normally present in the engine crankcase; As had been mentioned above, it has been standard practice in the past to attempt to use light lubricating oils for this purpose; it is obvious, however, from the very nature of the fouling material that mineral oil in itself is not a satisfactory solvent or cleaning agent. More recently, it has been found that superior results may be attained by using compounded fiushing oils comprising essentially a solvent for the lacquer deposits encountered, a detergent to loosen and/or emulsify the sludge deposits and suflicient lubricating oil to ensure,

safe operation during the cleansing period.

The instant invention relates to an improved compounded flushing oil of the type last described above.

The requisites of an effective flushing oil are:

1. It must be a good solvent for lacquer and resins.

2. It must have a suitable detergent action in order to carry away solid particles.

3. The flash point must be high enough to permit safe use in an engine.

4. It must not be corrosive, especially with regard to bearing metal alloys.

5. It should preferably have a relatively low 6. It must have suficient lubricating properties to ensure safe operation of an engine for at least short periods.

7. It should be sufliciently stable to withstand storage for long periods. I

According to the present invention, a composition containing the following ingredients hasbeen found to have all the above desirable prop erties: a highly aromatichydrocarbon material havng a wide boiling range such as, for example,

a blend of high viscosity lubricating oil or, alterder of 40 s. s. u. at 160 n), the determining factor of the proportions of these two constituents is that the final flushing oil composition viscosity (of the order of '100 S. S. U. at 100 F.). 1

natively, alubricating oil extract such as furfural extract, or similar aromatic extracts having a high viscosity and boiling over approximately the same range (that is, 300 F. to' 500 F. or more) at 1 mm. Hg., and a highly aromatic SQ: soluble petroleum extract having a boiling range of approximately 400 F. to 600 F. such as kerosene extract; a petroleum sulphonate which is either neutral or slightly acid as'a detergent; a lacquer solvent having high boiling and flush points such as diacetone alcohol; water. I

A preferred composition contains the above materials in the following proportion by weight:

Percent 150 s. s. U. at 2l0 F. lubricating oil or lubricating oil extract Kerosene extract (boiling range 410 F.-

' concentrate composition:

f Percent 200-230 S. S. U. at210 F. heavy lubricat ing oil 33 Highly aromatic petroleum extract boiling in the kerosene range 27 I Twitehells-Base No. 262 Diacetone alc 10 Water 4 10 This composition is diluted with suflicient light should have a viscosity of approximately 100 S. S. U. (seconds Saybolt Universal) at 100 F.,

.and in no case appreciably less than this.

It will thus be seen that the heavier the grade of lubricating oil or lubricating oil extract used, the greater the quantityof lighter aromatic petroleum extract that may safely be utilized.

It has also been found desirable at times to provide a flushing oil concentrate, this material being diluted with a light mineral oil before use.

The following has been found to be a satisfactorylubricating oil, usually about 1:1, to produce a final blend having a viscosity of approximately 100 S. S. U. at 100 F.

The recommended procedure for cleaning an internal combustion engine with the herein de- 510 F.) 34 Sodium salt of mahogany sulfonic acid 10 Diacetone alc h Water l The above flushing .oil composition hasa viscosity of 100 S. S. U. at 100 F. The flash point is above 150 F. as determined by the Pensky- Martens closed cup method (A. S. T. M. designationz D93). There is no phase separation upon storage and no appreciable semi-solid bottom deposits after subjection to four days storage at 40 F., five hours storage at 30 F. or one-half hour of centrifuging under 1000 g. force.

The relative quantities of the various constituents set out in the above preferred formula may be varied within certain limits without deleteriously afiecting the beneficial effects and desirable properties thereof to an undue degree. The water content may be altered from any value less than 1% to a maximum of 5%, depending largely uponthe tendency for an aqueous phase to separate. The tolerance of the composition with respect to water is largely dependent upon the aromaticity of the hydrocarbon blend used. The content of diacetone alcohol may be varied from 2% to a maximum of 10%. The amount of petroleum sulphonate may vary from 5% or less to as much as 25%, although more than 15% is not normally recommended. The product commonly known to the trade as Twitchells Base N0. 262

is preferably used for this constituent-being a sodium salt of mahogany sulfonic. acid plus a small amount of a stabilizing agent, suchas for example cyclohexanone. The lubricating oil or lubricating oil extract and aromatic lighter ex-' tract, such as kerosene extract, taken'to'gether, may vary from 60% to 85% of the composition. It is preferable to utilize as much of the lighter aromatic extract as possible, but since the viscosity of such extracts is usually low (of'the orscribed flushing compound is as follows: the crankcase is drained while the engine is hot to remove as much. of the old lubricating oil pres.- ent as possible; the crankcase is. then filled with the instantly described flushing oil composition, theengine started and operated at a fast idling speedfor one hour and the crankcase again drained; the crankcase is then filled witha lightmineral flushing oil, the engine started and operated for a period sufliciently long to remove any of the flushing oil composition held up in the various parts of the engine, after which the crankcase is again drained and is then ready for its-normal charge of lubricating oil.

Numerous laboratory and field testson various engines indicate that the cleansing treatment as described above results in removing a major proportion of all sludge and lacquer deposits in the oil rings, ring grooves,- oil holes, oil screen composition, the same extraction procedure followed, and as a result another 11 grams of insoluble, solid material was recovered after filtration.-

The results of this test indicate that the above flushing oil composition is nearly 6' times as effective in removing undesirable engine deposits as a light mineral oil.

We claim as our invention; I 1. A flushing oil composition suitable for re- .moving sludge and lacquerous deposits from internal combustion engines comprising substantially not more than 5% by weight of water, from 2% to 10% by weight of diacetone alcohol, from 5% to. 25% by weight of a sodium salt of mahogany sulfonic acid having a pH notexceedproportions by weight:

a viscosity of at least approximately 100 S. S. U. 5

at 100 F. and a flash point in excess of 150 .F.

A. S. T. M. designation: D93.

2. A flushing oil composition suitable for removing sludge and laoquerous deposits from in ternal combustion engines comprising the following constituents in the following approximate as determined by the closed cup method Percent Mineral lubricating oil having a viscosity of approximately 150 S. S. U. at 210 F 50 Highlyaromatic liquid sulfur dioxide soluble petroleum extract boiling in the kerosene rang Sodium salt of.mahogany sulfonic acid 10 maceboge alcohol 5 Water 1 JOHN A. EDGAR. HAROLD A. WOODS. 

